Normally AT&T would have handed off packets representing content requests, session IDs and other data – most of which travels unencrypted to and from Facebook – to Level3 Communications, which would hand them off to Facebook servers.

Instead they went the long way, through subnetworks owned by China Telecommunications, the state-owned ISP of mainland China, then to SK Broadband, a commercial ISP in South Korea, before finding their way to Facebook.

Facebook responded with a press release saying no Facebook traffic actually passed through China's geographic territory, leaving open the possibility it may have gone through a China Telecom-owned Chinanet server located in Europe or the U.S.

Facebook issued a statement that said:

We are investigating a situation today that resulted in a small amount of a single carrier's traffic to Facebook being misdirected. We are working with the carrier to determine the cause of this error.

Our initial checks of the latency of the requests indicate that no traffic passed through China.